Poorly differentiated non-small cell lung carcinoma presenting as a fever of unknown origin

Authors

Brandon Boyarsky, Internal Medicine, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA brandonboyarsky@gwu.edu.
Caroline Cox, Internal Medicine, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.
Sarah Boutwell, Internal Medicine, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA.

Document Type

Journal Article

Publication Date

1-29-2026

Journal

BMJ case reports

Volume

19

Issue

1

DOI

10.1136/bcr-2025-270547

Keywords

Chemotherapy; Fever of Unknown Origin; General practice / family medicine; Lung cancer (oncology); Screening (oncology)

Abstract

To achieve a definitive diagnosis of a fever of unknown origin (FUO), clinicians must consider infectious, autoimmune, neoplastic and other pathologies. While thorough history taking is crucial, it may not reveal the underlying aetiology behind the FUO. Several weeks of laboratory testing, imaging studies and advanced testing may be involved. We present the case of a woman in her 70s who came to her primary care provider with a primary complaint of FUO and describe the diagnostic steps, which identified a poorly differentiated, advanced non-small cell lung carcinoma. This case also highlights several missed diagnostic opportunities, including delayed imaging and diagnostic inertia, which contributed to the late identification of her underlying malignancy.

APA Citation

Boyarsky, Brandon; Cox, Caroline; and Boutwell, Sarah, "Poorly differentiated non-small cell lung carcinoma presenting as a fever of unknown origin" (2026). GW Authored Works. Paper 8513.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/8513

Department

Medicine